"자꾸" is an adverb, and it is often used to describe something which is quite frustrating or irritating happens repeatedly. :) \^o^/

I think it means to do something repeatedly. This sentence is translated to " my breath keeps stopping, you are walking toward me "

자꾸 is an adverb, it means "repeatedly" or "frequently"

자꾸 means 'keep' :)